3 32-ounce containers beef broth (enough to cover the oxtails)
2 cups dry red wine
2 medium onions, chopped
2 medium leeks (white and pale green parts only), chopped
3 medium carrots, peeled, very finely chopped
2 medium parsnips, peeled, cut into ½-inch cubes
6 garlic cloves, minced
1 6-ounce can tomato paste
1 teaspoon dried thyme
1 bay leaf
2 large russet potatoes, peeled, cut into ½-inch cubes
⅓ cup finely chopped fresh Italian parsley
Instructions
Heat 2 tablespoons oil in heavy large pot over medium-high heat. Sprinkle oxtails with salt and pepper. Add oxtails to pot and brown on all sides, about 20 minutes. Add beef broth and 2 cups wine. Bring to simmer. Reduce heat to medium-low. Cover partially and simmer gently until meat is tender, stirring occasionally, about 3 hours.
Using tongs, transfer oxtails to large bowl. Carefully pour cooking liquid into large bowl. Refrigerate cooking liquid overnight until fat separates from liquid. Spoon fat from top of cooking liquid. Remove meat from oxtails; discard bones. Add meat to cooking liquid. (Can be made 1 day ahead. Cover and chill.)